Evaluation of the milk yield performance of Jersey cows under tropical climatic conditions in Nigeria

A A Adebayo and S O Oseni

Abstract

The objective of this study was to assess performance and environmental
factors affecting milk yield of Jersey cows under a humid tropical
environment. The research was conducted at Rosedale Dairy Farm located in
Shonga, Kwara State in North-Central Nigeria. Secondary data used for this
study included 800 milk yield records of 200 cows across three parities and
four seasons (early rain, late rain, early dry and late dry) from 2008 to
2012. Variables analyzed included total lactation milk yield (TLMY), days
dry (DD) and lactation length (LL).

Data were analyzed using Univariate and General Linear Model procedures of
SAS®. Results showed that overall means of TLMY, DD and LL were
2160±34.9 Kg, 87.5±2.52 days, 302±1.96 days, respectively. The TLMY and DD
were significantly affected by parity and season of calving (P< 0.05). In
contrast, parity and season of calving had no significant effect on LL (P>
0.05). Two-way interactions between season and parity of calving were not
significant (P>0.05). Z-statistic showed that TLMY (of 2160Kg) recorded was
significantly lower (P< 0.05) than that of Jersey cows in Cameroon, West
Africa. Large scale evaluations across multiple ecological zones are
required in order to establish the true performance of Jersey cows in hot
and humid conditions and in the West African sub-region.

Keywords: days dry, humid tropics, lactation, parity

Introduction

In Nigeria, there had been significant decline of locally produced milk over
the years as evidenced by closing down of several dairy plants, or the
conversion of existing plants to recombination processing units, as well as
heavy importation of milk powder and ready-to-use dairy products as raw
materials for industrial processing (Gisanrin, 2014). This trend clearly
shows the absence of a policy and institutional framework for sustainable
long-term dairy sector development in Nigeria.

There is a diversity of dairy breeds that are adapted to different
ecological zones globally. In hot and humid climate, there is a challenge of
reduced performance of some of these breeds, due to a combination of
factors, including unfavourable ambient conditions (especially temperature
and relative humidity), low level intensification and management practices.
Jersey cows are however, known to be hardy and adaptable to a wide range of
climatic and geographical conditions (Hilton and Briggs 1980). With all
these attributes of this breed, knowledge of its performance in different
production systems and agro-ecologies in the humid tropics can be useful for
strategic planning and development efforts for the dairy sector in Nigeria.
Also, this knowledge would be a practical tool for the development of dairy
cattle farming systems, especially in developing nations where demand for
milk production is expected to increase by 25% in 2025 (Delgado et al 1999),
partly due to population growth, but also because increasing disposable
income will be spent on a greater diversity of food products to meet
nutritional needs. Therefore, the objective of this study was to evaluate
factors affecting the productivity of Jersey cows under the hot and humid
tropical climatic conditions of Shonga, North-Central Nigeria.

Materials and methods

Experimental Station

The study was carried out at Rosedale Dairy Farm at Shonga, Edu Local
Government, Kwara State in North Central Nigeria. Its geographical
coordinates are Latitude 9° 1'N and Longitude 5° 9'E. Its climate, which is
tropical savanna, exhibits a well-marked rainy and dry seasons. The average
annual temperature in Shonga is 27.9 °C and the average annual rainfall is
1146 mm (Climate-data, 2014).

Management practices

Detailed management practices by the owners of the Dairy Farm included the
following. Animals are allowed to graze around their sheds and in the
fields. Also, concentrates are given to the cows as supplementation feeds.
Feed ingredients in the concentrate included crushed dried whole cassava,
palm kernel cake, brewers dried grain, soybean, dried sorghum, sunflower
cake and occasionally, molasses are added. Salt blocks were provided and
cows were allowed access to drinking water always. After calving, calves are
allowed to stay with the dams for four days for access to colostrum and
weaned at 3 months of age. After weaning, each calf was bottle-fed with 4 Kg
of milk per day, spread across three portions to aid digestion.

Daily management practices included identification and treatment of any sick
cow, taking the cows out to the field for grazing, hygiene and sanitation,
and provision of feed and water. Daily or routine management practices also
included milking of the cows, and feeding of the calves. A semi-intensive
system was practiced. Well-ventilated sheds were constructed for the milking
cows to reduce the effect of heat stress. The cows are milked twice a day,
in the morning (at 6 A.M.) and in the evening (at 4 P.M.), with the aid of
milking machines. The milking machines were always washed before and after
each milking to prevent incidence of mastitis. Cattle are always taken out
for exercise twice a month to walk about six to seven kilometers. Their
water trough is washed thrice a month, water stored inside the tank is
treated chemically twice a month and their sheds are washed every day. Once
a week, their sheds are always fumigated and disinfected and their dung is
packed every day.

Datasets for the study

The dataset consisted of 800 cumulative milk production records of 200 cows.
The data was analyzed to evaluate milk yield performance of Jersey cows
under hot and humid climatic conditions. Variables in the dataset included
total lactation milk yield (TLMY), days dry (DD) and lactation length (LL),
season of calving, and parity of cows. In order to remove incomplete or
inconsistent records, Total milk yield was restricted from 1000 liters
upward per lactation. The records of days dry were restricted from 30 days
to 210 days. Records of lactation length below 250 and above 365 days were
expunged. In all, 1 st to 3rd lactations were
evaluated, since the fourth lactation records were largely incomplete. Four
seasons of calving were established based on weather and climatic conditions
of the area: early rain (April- June), late rain (July- September), early
dry (October- December) and finally late dry (January-March).

Data Analysis

Data were summarized using Microsoft Excel and then analyzed using
Univariate and GLM procedures of SAS® (2003).

The following model was fitted:

Yijk = μ + αi + βj + (αβ)ij +
εijk

where Yijk = (TLMY, DD or LL) that is, the kth lactation
record of the jthseason of calving of the ithparity

μ = population mean,

αI = effect of ith parity (i = 1...3),

βj = effect of jth season of calving ( j= 1…4),

(αβ)ij= interaction between jth season of
calving and ith parity and

εijk = residuals associated with each Yijk, assumed to
be normally and independently distributed with mean zero and constant
variance.

Results and discussion

Descriptive statistics of milk yield traits are presented in Table 1. The
means for total lactation milk yield (TLMY) was 2,160 ± 34.9 Kg with minimum
and maximum values of 1001 and 4498 Kg respectively. The means for lactation
length (LL) was 302±1.96 days with minimum and maximum values of 250 to 365
days respectively. Days dry (DD) had an overall mean of 87.5 ±2.52 days with
minimum and maximum values of 30 and 210 days respectively. High
coefficients of variation for TLMY, LL and DD indicated high variability in
the performance of Jersey cows evaluated for these traits.

Table 1.
Descriptive Statistics of the variables recorded

Variables

n

Mean

S D

SEM

Min.

Max.

CoV

Skewedness

Kurtosis

TLMY(kg)

468

2160

754

34.9

1001

4498

0.35

0.49

-0.30

LL (days)

235

302

30.1

1.96

250

365

0.10

0.33

-0.80

DD (days)

349

87.5

47.01

2.52

30

210

0.54

1.25

0.36

TLMY= Total Lactation Milk Yield, LL= Lactation Length, DD= Days Dry

Total lactation milk yield

The least squares means of total lactation milk yield (TLMY) as affected by
parity and season of calving are presented in Table 2. The overall TLMY mean
of 2160±34.9 Kg is higher than the result of Adeneye and Bamiduro (1977) who
reported a value of 1257 Kg for Jersey cows in Western Nigeria. Similar
finding was reported by Bagherwal and Khan (1991), Juneja et al
(1991) and Mutukumira et al(1996) from India and Zimbabwe who all
reported TLMY of 2141.3± 160 Kg, 2147± 670 Kg and 2226 Kg respectively for
Jersey cows. The milk yields for first, second and third lactation were 1769
Kg, 2273 Kg and 2458 Kg respectively, indicating a rising trend for TLMY
with parity (P<0.05). These values are however, lower when compared to the
findings of Nandolo (2015) in Namibia who reported 2250 Kg, 2510 Kg and 2850
Kg for Jersey cows in their first, second and third lactations,
respectively. The difference in the performance of Jersey cows from
different reports could be due to management as well as the genetic
background and degree of adaptability of the Jersey cows in the different
agro-ecologies, as well as the level of intensification of the dairy
operations under which the cows are raised and managed.

Total Lactation Milk Yield was significantly affected by parity (P< 0.05)
(Table 2). First lactation cows had the lowest milk production (1769± 126
Kg) while the highest production (2458± 126kg) occurred in cows in their
third lactation. Similarly, Kemenes et al (1994) and Javed et al (2002)
reported that parity had significant effect on TLMY of Jersey cows
maintained in Brazil and Pakistan, respectively.

Season of calving significantly affected the TLMY (P<0.05) (Table 2). When
the data were grouped according to the season of calving, maximum milk
production (2534±78.5 Kg) occurred during early dry season of calving, while
the lowest production (2023± 105 Kg) occurred in the early rainy season.
Tesfaye and Alemu (1993), Kemenes et al (1994) and Javed et al. (2002) also
reported a significant effect of season of calving on TLMY for Jersey cows
raised in Ethiopia, Brazil and Pakistan, respectively. However,
non-significant effect of season of calving on TLMY had been observed by
Morsey et al (1989) in Libya and Bagherwal and Khan (1991) in
India. The seasonal differences that exist might be due to feed quality and
availability associated with different times of the year.

Figure 1 showed the Tukey’s Box and the Whisker plots which displayed the
range, median and the quartiles of TLMY data at different lactations. This
plot summarized the performance of the cows in each lactation. The TLMY in
the third lactation (parity) was the highest out of the three lactations as
a result of the superior performance in TLMY for that lactation. This is in
accordance with the report of Lateef (2007) that milk yield increases up to
third lactation and it remained fairly constant in the fourth and fifth
before it starts to decline thereafter. These observations could guide
management on the strategies to maximize milk yield and income as a result
of the increasing TLMY with parity.

One Sample Z-test for the Total Lactation Milk Yield was performed to
determine whether the mean milk yield of these Jersey cows calculated from
the data was statistically different from the mean milk yield of Jersey cows
from the West African region (Table 3). This was done since the countries
have near similar agro-ecologies and climatic conditions. It can be
concluded that TLMY means (2160Kg) derived from the data was significantly
lower when compared with the mean Total Lactation Milk Yield (2681 Kg) of
Jersey cows in Cameroon as reported by Bayemi et al(2005)
(P<0.05). Reasons for this could be due to differences in management as well
as the level of intensification of dairy operations. It is noteworthy that
reports of the evaluation of Jersey cows for milk yield in the West African
sub-region are scanty. While the current comparison may indicate lower
performance of Jersey cows in North-Central Nigeria, large scale evaluations
across multiple agro-ecologies are needed to draw precise conclusions.

Days dry

The least squares means for days dry (DD) as affected by parity and season
of calving are presented in Table 2. The overall mean for DD of Jersey cows
was 87.5±2.52 days, ranging from 30 to 210 days. Such a long range for DD
across three parities reflect variations in performance of Jersey cows
evaluated. Deshpande et al (1992) reported similar results for DD (86.6
days) in India, Tesfaye and Alemu (1993) and Gogoi et al(1993)
reported average dry period for Jersey cows maintained in Ethiopia to be 128
days and in India to be 233.5 days, respectively, which were longer than our
findings. Days dry, by definition, represent a non-lactating period prior to
an impending parturition to optimize milk production in the subsequent
lactation. Prolonged DD contributes to extended calving intervals which
affect the operational efficiency and profitability of dairy operations.

The effect of parity was significant on days dry of Jersey cows (P <0.05)
(Table 2). Jersey cows at the second parity had the highest dry period and
it was significantly different from the cows in the first and third
parities. This agrees with the report of Sadhana and Basu (1983) who
reported that parity was a significant factor affecting the dry period of
Jersey cows in India. However, Murdia and Tripathi (1992) and Sattar et al
(2004) reported that parity had no significant influence on days dry in
India and Pakistan.

Season of calving has a significant effect on days dry with the cows that
calved in early dry season having the lowest days dry (68.6± 5.74) (P<0.05)
(Table 2). Early dry season calvers were significantly different from the
rest – such cows recorded the lowest dry periods. A non-significant effect
of season of calving on dry period of Jersey cows have been reported by
Katoch et al(1(1991), Deshpande et al (1992) and Murdia and Tripathi
(1992).

Lactation length

The least squares means of total lactation milk yield as affected by parity
and season of calving are presented in Table 2. The means of the lactation
length was 302±1.96 days, with a range of 250 to 365 days. This is higher
than the report of Adeneye and Bamiduro (1977) who reported a mean of 248·4
days in Nigeria. Mutukumira et al (1996) reported a similar lactation length
of 280 to 300 days in Zimbabwe. However, Tesfaye and Alemu (1993) and
Kemenes et al (1994) reported higher lactation length of 294±5.5 days in
Ethiopia and 314±6.1days in Brazil, respectively. Long lactation length
increase calving intervals, thereby leading to reduced cow productivity
(Ngongoni et al 2006). Short lactation lengths result in low milk
production, while a 305-day lactation length is a commonly accepted standard
in most modern dairy farms (Wondifraw et al 2013).

Parity had no significant effect on lactation length of Jersey cows (P>
0.05) (Table 2), implying a conscious management decision to maintain a
consistent range for LL across parities. This agrees with the results of
Sattar et alm(2004) who reported a non-significant effect of parity
on lactation length of Jersey cows in Pakistan. In contrast, Match and Tomar
(1983) reported that parity had a significant effect on the lactation length
of Jersey cows.

Season of calving had no significant effect on the lactation length (P>
0.05) (Table 2), implying that irrespective of the season of calving, a consistent LL was
practiced by the management. This is in agreement with the reports of
Deshpande et al (1992) and Rao and Rao (1997) who reported a non-significant
effect of season of calving on lactation length in Jersey cows in India.
Murdia and Tripathi (1991) and Kemenes et al(1994) reported a
significant effect of season of calving on lactation length of Jersey cows
in India and Brazil respectively. Lateef (2007) reported that the results of
Katoch et al(1991) from India showed that lactation length of
Jersey cows was longer in the rainy season.

Table 2.
Effect of Parity and Season of Calving on Total Lactation Milk Yield, Days Dry and Lactation Length

Conclusion

Results showed that total lactation milk yield increased with parity, with
highest yield recorded in the third lactation.

The performance of Jersey cows was lower when compared with results from West Africa and other
regions.

Large scale evaluations across multiple agro-ecologies are needed
to draw precise conclusions.

Acknowledgements

This study was done under the DelPHE programme (DAIRYLEARN), funded by the
DFID (UK) and managed by the British Council. Worthy of mention are Mr. &
Mrs. Reid of Rosedale Farm, for their permission to use their data. The
final data analysis and write ups also benefitted from the DairyChain
(www.dairychain.org) project funded by the European Union.

References

Adeneye J A and Bamiduro T A 1977
Causes of variation in milk yield and lactation length of Jersey cattle in
Western Nigeria. Journal of Agricultural Science 89:209-214.